Investigation of Welding Parameters Effects on Residual Stresses of Resistance Spot Welding of AZ31 Alloy

In this study, the effect of welding parameters on the residual stresses of resistance spot welding of AZ31 magnesium alloy was investigated. Resistance spot welding is a complicated multi-regime phenomenon which simulated by a developed electro-thermo-mechanical coupled finite element model. Interactions of parameters were determined using DOE method. The FE model was used to predict temperature changes, nugget growth, and the residual stresses distribution. The results of the simulation were validated with experimental data, based on the nugget diameter. The results showed that by increasing current and welding time the residual stresses are reduced. Increasing electrode force causes to increase residual stress but increasing holding time creates a peak in the amount of residual stresses. Also, evaluation of current sources revealed, in the same conditions, using direct current creates less residual stress than alternating current.